


Lab Partners (In Crime)

by Cricketii



Category: Undertale (Video Game)
Genre: Angst with a Happy Ending, Dorks in Love, F/M, Female Frisk (Undertale), Fluff and Angst, Jealousy, Love, Mating Cycles/In Heat, Possessive Sans (Undertale), Pranks, Racism, Reader Is Not Chara (Undertale), Reader Is Not Frisk (Undertale), Reader-Insert, Sans (Undertale) Remembers Resets, Sans Is Taller Than The Reader, Sans hates humans, Scientist Sans (Undertale), Slow Burn, They're basically two highly intelligent idiots
Language: English
Status: In-Progress
Published: 2020-04-26
Updated: 2020-04-26
Packaged: 2021-02-28 21:42:09
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,765
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23334046
Author URL: https://archiveofourown.org/users/Cricketii/pseuds/Cricketii
Summary: When eccentric, over-the-top human meets reserved, comical monster, what could go wrong?Turns out many things, many things could go very, very wrong.But who would've thought that pairing two of the biggest pranksters in the scientific project of the year could ever have negative repercussions?
Relationships: Sans (Undertale)/Reader
Comments: 5
Kudos: 60





	Lab Partners (In Crime)

**Summary for the Chapter:**

> When eccentric, over-the-top human meets reserved, comical monster, what could go wrong?
> 
> Turns out many things, many things could go very, very wrong.
> 
> But who would've thought that pairing two of the biggest pranksters in the scientific project of the year could ever have negative repercussions?

_Humans were such sad creatures, they had been before the war and were even more so now._

_They were so desperate for a power that they would never achieve, so they had resorted to technology, and even that was so primitive in comparison to the advanced levels of science that monsters had achieved with the limited resources that the underground offered._

_The funny part was that it was the humans fault that they were so behind in terms of intelligence. If they just kept to the truce all those years ago instead of being jealous, judgmental bastards, they could have become so much more advanced as a race._

_Look at them now though, such prideful little beings. They seemed to think that they had become such an exceptional people... idiots, they didn't even have magic anymore, serves them right though._

_Their jealousy was still ever present though, due to their lack of magical abilities they had decided that monsters wouldn't be allowed to use magic either, banning the use of it from any public places that humans could be present in, with very few exceptions._

_..._

_Damn sons of-_

"S-Sans? Did you... hear me?" Alphys' gentle, shaking murmur broke through his slowly descending thoughts.

He blinked once, his vision refocusing on the carpeted floor he was staring at so intensely, a shallow breath escaped from his nasal cavity. His previously tense shoulders rolled back into a comfortable slouch, his rigid expression dissolved, leaving a casual grin in its place.

"sorry alph, didn't hear ya come back." He admitted, eye lights rolling over to meet her gaze. The shorter yellow dinosaur monster was staring at him, uneasy, she had abandoned her lab coat and work clothes for a pair of "Mew Mew Kissy Cutie" themed pajamas. Her grip on the tray holding their drinks and snacks was tight, anxious. 

"You u-umm... were st-staring at the floor... r-really hard I uh..." She fumbled over her words, eyes travelling away from his own, "I was j-just asking if you were a-alright." 

...

He immediately noticed how her fidgeting and stuttering were more prominent than usual.

"...heh." He shut an eye socket, his signature look that only ever meant one thing, "i guess i just really like looking at it, keeps me _grounded_." 

The female monster sighed, her nervous smile returning, as she handed him his drink of choice, setting the tray down on the short coffee table a few feet away from them. His weight shifted only slightly as she sat down next to him.

She decided to remain silent as she reached for the TV remote, shutting off the news broadcast just as the human news anchor on the screen began debating whether or not monsters should be allowed to vote. He didn't have to thank her, he knew that the way his death grip on the arm of the couch loosened was enough of a sign of his gratefulness.

The two were fairly silent as they took sips from their respective mugs.

...

"i got the job."

"W-wait WHAT?!" Her outburst made him flinch the slightest bit, she settled back down after clearing her throat, "S-sorry i-i-it's just that..."

"what? didn't expect me to get in? i'm hurt." He placed his skeletal hand over his sternum, feigning heartache.

"N-no! It's not- I-I'm not- I just really d-didn't think you were going to apply in the f-first place!" She explained herself, fumbling with the hem of her shirt, "I kn-knew that you'd get in if you applied... y-you're the smartest person I know."

He took another long sip from his mug, "aww, thanks alph, i'm flattered." His tone was joking, but sincere.

...

"Why'd you decide to go for it i-in the end?" Her voice had gone quieter again.

He thought back to why he had first gotten the offer from the research facility. They had only wanted him because he was the only monster that was involved with the lab back in Hotland that was still unemployed, he was aware of that. He really, _really_ didn't want to work with humans, he dedicated an entire night to reasoning it out with the other scientist that now sat next to him. He thought he had made up his mind but...

"it's a government funded project, the pay's great. with the money that they're offering, it'll help drastically with keeping me 'n pap afloat while he's completing his courses." He was fine with admitting that it was just for the money, not to actually assist in any breakthroughs that the humans planned on making.

"That's u-understandable..." She pushed herself into the backrest of the couch, struggling for a moment to repel herself as her feet came off the floor, "How long are you p-planning on working there for?"

"they got a special contract done up for me, i'm legally obligated to work with them at least until the end of the year."

"..." Her brows furrowed, "Sans, th-that's almost six _m-months._ " 

"i'm aware." 

"A-are you sure you'll be alright w-with that?" Her whole body was turned to him now, "I-I know that you didn't want to take the job t-to begin with."

Even the mention of what was about to take up a half a year of his life made him cringe.

"not sure if i'm alright with it, but... i'll manage, y'know?" He shrugged, knocking back the rest of the ketchup that filled his mug, "i only have to work with one of 'em, a _partner._ " 

His friend settled down, pushing her round framed glasses further up on her face, "Well I guess that's not _a-as_ bad..."

...

"S-so umm... when do you start?"

He leaned forward, placing his mug on the coffee table, his solemn expression perfectly displaying how enthusiastic he was for the things to come with his new occupation.

"...tomorrow."

* * *

"I, honest to god, think that this is the most excited I've ever seen you, and that's terrifying." Your roommate teased, watching you inquisitively from her spot on your shared sofa, although her impudent behavior fell on deaf ears as you tugged your sneakers on eagerly.

You had been waiting for this day for _months,_ there wasn't too much that could put a damper on your mood in a state like this.

"Damn, you _are_ thrilled as hell..." She seemed to be less amused by your enthusiasm when she came to the realization that she couldn't mess with you about it, it was all in good fun though, "Why are you so pumped up again?"

You turned back to her a little bit faster than you meant, eyes gleaming with exhilaration.

"Oh god no-" She started, only to be interrupted, realizing the hole she had dug herself into when it was already too late.

"So we've been waiting to start research into souls for- well, ever since monsters came to the service and told us about them. The government took _forever_ to give us the okay, stating that it could be considered ' _unethical_ ' to some people." You began your rant, using physical air quotes at some parts. Your tone was vivid, every word brimming with pure emotion.

"Is it not unethical?" Your roommate asked, raising an eyebrow.

"Maggie, people have been dissecting human bodies for hundreds of years, if human souls can be maintained after death, why wouldn't we be able to do the same to them?"

"Fair point." She surrendered immediately, knowing far better than to attempt to play devil's advocate with someone as relentless as you.

"Anyways, the government finally said that we could go through with the project and that they would give us the funding... under one condition." You tone went a little more serious, "We needed to get at least one monster on our team."

"That's... _not_ a good thing?"

"Not when the only reason it's being done is so that the government looks good for being inclusive. They made it so painfully obvious when trying to recruit monsters onto our team that they only wanted them around for brownie points and a gold star from the public that it just... it just messed up any good relationship that we'd be able to form with any of them." You sighed indignantly, agitation seeping into your joy as you stuffed your documents into your backpack with vigor.

"Wait, why did the government recruit monsters onto your team?" The tan woman sat up from her previous lounging position, getting invested in the story.

"They basically took ownership of our project, so they took charge in recruiting any possible candidates." 

_They also added some ludicrous contract that gave them ownership of your time, life, body and firstborn child-_

"But yeah, long story short they scared away the majority of the possible candidates, had to bump up the pay, finally got one to join our team..." You continued on, talking in a nonchalant tone... for about seven seconds.

It was like a switch had flipped as you burst back into action, "And now after eight months of waiting, we get to begin our research, STARTING TODAY!" You exclaimed, zipping up your backpack with beaming smile.

A small smirk crossed Maggie's face as she noticed how energy practically radiated off of you, "So you're gonna be working with a monster, huh?"

"Well I actually don't know if I'll be working with them, we've set it up so we'll be working in pairs, each pair designated to a specific but not limited area of research. There's twenty two of us, so I've got a one in twenty one chance of having them as my partner, so..."

"So what, like a fifteen percent chance or something?" She asked, her black shoulder-length curls rolling to the side as she tilted her head, she was using her brain, just not very well, per usual.

"Try a five percent chance," you grinned at her, she mimicked your expression, "I don't really care if I'm partners with them or not though, it's just nice to have them on the team, you know?" 

"I suppose, are you heading out now?" She asked, pushing herself up off the couch to stretch.

"Yeah, be a doll and actually do some work today, alright?" Your jokingly snarky comment earned a tongue stuck out and a crude gesture via finger from Maggie, you only laughed in response.  
  


”Yeah yeah, how about you try to actually make a _good_ impression this year?”

You knew exactly what she was throwing in your face before the words even left her mouth. You could even hear her begin to question if she had crossed a line as she brought her sentence to an end.   
  


It certainly hadn’t made for the best year when you completely and utterly screwed up any possible friendship you could have formed with your previously assigned partner. You were just so excited, you had worked alone for so many projects, it would be so refreshing to have a partner, a friend, to help you.  
  


Turns out that excitement and hot coffee weren’t the best mixture, especially when an expensive laptop with months of research stored on it was added to the equation.

A regretful look settled into your face, eyes and nose crinkling into a cringe as you recalled the event as if it were a film in the back of your mind. That memory ate away at you more often than you liked to admit.

A gentle sigh escaped through your nose as your features relaxed, allowing the memory to be a memory, nothing more. Your lips tugged up at the corners into a smirk,

“Yeah, I’ll try.”   
  


A blissful relief washed over the room as it’s two inhabitants reminded themselves that neither could ever hold anything against the other.   
  


The conversation was left there as you both said your goodbyes.

* * *

  
Being only a few blocks away from the laboratory you worked at, you had always opted to walk to work, despite having a car and access to public transportation at your disposal. It was only in more severe weather like thunderstorms or hail that had deterred you from your usual stroll.

Today, however, had to be written somewhere in the dictionary under _perfect._   
  


The sun was out, but would periodically pass behind a cloud for just long enough to give seemingly timed intervals of warmth and shade. There was also a slight breeze, but it was warm, the kind that gently encased your body in a blanket of comfort every time it passed by.   
  


Being late June, it wasn’t exactly uncommon for this type of weather to occur, but never this absolutely, insanely perfect. It was like the heavens themselves had decided to bless you on your first day.

The best part was that you lived in a mixed community, one of the only ones that existed.

_’So far.’_ You reminded yourself.

Everyday you got to pass by and see two different peoples begin to integrate and mingle and join together to become a community over time. It started out slow, casual, if not a little forced, conversations starting up here and there with considerable apprehension was all that anyone got for awhile. Eventually though, people starting inviting others over, monsters began getting more job opportunities and invites to events. Soon enough, neighborhood get-togethers were even larger, traditions and celebrations were shared among cultures, race slowly became less of a barrier and more of a singular trait, nothing to focus on.  
  


Hell, history was in the making and here you were, moseying along the sidewalk, watching as it all took place. What a time to be alive.

You shuffled to the side to just narrowly dodge a couple kids as they ran past, chasing after a soccer ball. It didn’t even phase you that one was human and the other was a large frog monster, and you were overjoyed with that.

The laboratory was already in view, even though you were only about halfway there. It was a large, four story grey brick building, covered with windows and plenty of entrances and exits.   
  


It had struck you once, during one of your many, many, _many_ walks to work, how much your workplace stuck out. Not because the building was anything special, but because of how it paled in comparison to the marvelously unique architecture that monsters had brought with them to the surface. Some buildings were relatively normal, even with their unique flair, but there was literally two igloos in your neighborhood now. In summer. You had even checked if they were actually made of snow when they were first built, the answer was yes... kind of. It was formed with magic. Magic snow? You weren't entirely sure but it was certainly something of the sort. Whatever the case, you had seen monsters enter into one and then pop out of the other, which was all the way down the street, within seconds. Magic snow teleportation igloos. What's more unique than that?

You had passed down this route at least twice every workday, and yet there was always some new fantastical wonder to enjoy. Yesterday there was a dog monster that passed by, it was a bit taller than you but it was nothing too noticeable. On your way back though... good god, it's neck had to be at least double the length of a giraffe, and there was two kids at the bottom, petting it relentlessly. No monsters seemed too phased by it, so you figured that this must have been a regular occurrence, as strange as it was.

It was a good strange though.

Your eyes trailed up to the gate of your workplace, it was a tall, metal fence with an electric card scanner just to the side of the gate. A metal plaque with the words "Kismet Laboratories" engraved into it was bolted into the brick, you could feel your adrenaline beginning to pump through your veins already. You clumsily pulled your key card out of your pocket and pressed it to the scanner, bouncing on the balls of your feet in anticipation. The entrance made a few clicking noises, then a long, deafening buzz, before beginning to slide open. You made your way up the path that was intended for cars, moving to the side a couple times for your colleagues to get through, giving them a friendly wave as they passed by. You could barely contain yourself by the time you got inside.

You had used your key card once again to actually get inside the building, pushing open the metal door, hot to the touch from the sun, and slipped inside. You were immediately met with a blast of refreshingly cool air from the building's air conditioning, as powerful as always. 

  
After some more checking in that seemed to drag on for way too long, you made your way over into the break room, you had been told that your sheets for work arrangements would be there. You just hoped that there wouldn’t be too many people wanting to talk to you, being incredibly antsy to just get to work.

...

You didn’t even get your hand on the doorknob before you were dragged into a conversation.

"Damn, I want some of whatever you're taking."   
  
  


The familiarly smooth tone of one of your colleagues halted your movements. You spun around on your heel to face the man that had decided to tease you as so many people seemed to enjoy doing.

”Sorry Alec, but it’s not for sale.” A grin found its way onto your face as you stared up at him, even if you were mildly irritated, that wouldn’t dissuade you from being nice. Although, something was off when you looked at him properly, “Wait, did you get a haircut?”

He ran a hand through his blonde hair, it had gone from shoulder length to just above his ears, “Hell yeah, you like it?” He purred, raising an eyebrow. You could see through what he was doing as if it were glass.  
  


“Not enough to go on a date with you.” Your grin had turned sly, if not a little irked.

You chose to cut things short there, as much as you wanted to be nice, you had a feeling that he’d start pleading with you like he usually did. You really didn’t feel like dealing with that today.

”Anyways, I really gotta get to work so uhh...” Just as you went to turn back around he handed something to you, a piece of paper.

Upon closer examination you realized that it was your working arrangement sheet and schedule, you blinked dumbly at it for a moment before taking it.

”Before you ask, no, I didn’t read it or anything, although it was tempting. Honestly though I just noticed that all the files were kind of hard to get through and thought you’d get annoyed with it. I know how excited you’ve been for today.” He smiled, much more genuinely this time. It suited him.

”Speaking of you being excited, I’m sure you’re probably desperate to go and get down to business so I won’t keep you.” He surprised you more with every word, he was so different from the clingy, desperate guy you had come to know so well. It seemed his haircut wasn’t the only thing that changed.

You couldn’t help but smile back in a way similar to his, he had changed, but you certainly weren’t complaining.

* * *

  
Checking the sheet in your hands, wrinkled from squeezing it in excitement, you clarified that the door in front of you lead to the right station, _your_ station.

Actually, you weren’t sure if it was correct to label it as yours, seeing as you were sharing it with someone, whoever that someone may be.  
  
  


You peered up at the black text on the metal surface of the door, confirming for the third time that it was a match.

Your fingers slipped into a grip around the door’s handle, your fingers curling around the smooth metal. You felt _determination_ pumping through your veins.

_Time to make a great first impression._

In one smooth motion you swung the door open, opening your mouth to speak with a beaming grin on your face and-

You stopped. Dead in your tracks.

There he was, the monster that your team had been talking about for weeks. The one that had graced you with the right to study something so advanced. The one that had _already_ studied said thing and could offer knowledge that other scientists would _kill for._ There he was, sitting at the station across from yours.

The, upon closer inspection, skeleton monster was typing away on a model of laptop you didn’t recognize, presumably monster technology.

  
You were surprised, sure, but that wasn’t what had made you stop.

The cause of your abrupt pause was instead the words that you had vowed to yourself before you had even entered the room.   
  


You wanted to make a great first impression, he looked really busy though, and you knew that you had to fill out your forms and legal stupidity just as he seemed to doing...

...

  
Your smile fell only slightly as you sighed to yourself, you could introduce yourself later, sometime when he wasn’t already doing something...

...and maybe when there wasn’t coffee right beside his laptop.

You shook off any bits of disappointment that had started to claw their way into your brain, knowing full well that you had months ahead of you to get to know your new friend-to-be.   
  


After successfully bringing back the spring in your step, you made your way over to the swivel chair and long table on the opposing side of the room.   
  
  


It would be fine, you continued to remind yourself that as the gap between you and your workspace came to a close.

You had gotten so deep into your thoughts, in fact, that you almost didn’t notice the noise that filled the room when you sat down.

_PBBBBFFFTTTTTT!_

You deadpanned, it took a moment for you to actually sit up and examine the culprit of the crude sound. You raised an eyebrow at the pale red, now deflated, balloon like contraption that sat there.

”A... whoopee cushion..?” You couldn’t help but mutter it to yourself out loud, beyond confused at this point. How did it get there?

Your question was answered by a quiet laughter, almost silent, that rang out behind you, the true culprit revealing himself shamelessly.

...

You couldn’t help the giggles that bubbled up out of your throat, taking the flattened practical joke and pocketing it to give back later.

_You could already tell that this was going to be much better than last year._

**Notes for the Chapter:**

> Hey, great job, you made it to the end of the chapter! This is my first book on here so I hope you enjoyed it. Also the art was done by myself, not sure if I have to clarify that on here. 
> 
> Anyways, that’s about all I have to say, fingers crossed that you enjoyed the book so far!

**Author's Note:**

> Hey, great job, you made it to the end of the first chapter! This is my first book on here so I hope you enjoyed it. Also the art was done by myself, not sure if I have to clarify that on here. 
> 
> Anyways, that’s about all I have to say, fingers crossed that you enjoyed the book so far!


End file.
